Mattel offered these cute 10" musical dolls in the mid-70s.  All are marked ©1974, but I have no idea how long they were marketed or if they came out all at once, or in stages.  They each have a vinyl head and rooted hair.  By pressing on the notes on their arms, legs, and tummies, you could play a musical note by forcing air into their otherwise hollow bodies.    Each tone was different allowing you to play simple nursery rhymes like Mary Had a Little Lamb, and Baa-Baa Black Sheep, etc.  I'm sure that each probably came with a booklet of instructions and song selections, but I found each of these dolls loose so I'm afraid I do not have very much info on them.  These shown are only four of the styles.  Not sure how many were offered but I have since seen a girl African American version as well.

Each may have a name but again, I am not sure.  An interesting note is that the redhead to the right has a zippered body while all the others are stitched in the back. She also has a lot more hair than another redhead I have, with an actual hair seam for two pigtails.